Method and apparatus for forming selvages on cloth



March 10, 1970 s. PFARRWALLER 3,499,474

METHOD AND APPARATUS FOR FORMING SELVAGES 0N CLOTH Filed Dec. 2'7. 196'?5 Sheets-Sheet 1 Fig. 1 1s 9 13' Inventor: Ervgi n Pfurrwoller ATTORNEYSMarch 10, 1970 E. PFARRWAILLER 3,499,474

METHOD AND APPARATUS FOR FORMING SELVAGES ON CLOTH Filed Dec. 27, 196; 5Sheets-Sheet 2 Fig. 2 Fig. 3

Inventor:

Erwin Pforrwclller ATTORNEYS March 10, 1970 E. PFARRWALLER 3,499,474

METHOD AND APPARATUS FOR FORMING SELVAGES ON CLOTH Filed Dec. 27, 1967SSheets-Sheet 5 Inventar:

Ervgin Pfurrwcller l ma MMYQQM ATTORNEYS March 10, 1970 E. PFARRWALLERMETHOD AND APPARATUS FOR FORMING SELVAGES ON CLOTH Filed D80. 27. 1967 5Sheets-Sheet 4 Inventor:

Erwin Pforrwuller BY FM MQ ATTORNEYS March 10, 1970 METHOD AND APPARATUSFOR FORMING SELVAGES ON CLOTH Filed. Dec. 27, 1967 E. PFARRWALLER 5Sheets-Sheet 5 & to 2*,

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Inventor:

Erwin Pfurrwoller BY ATTORNEYS United States Patent O 3,499,474 METHODAND APPARATUS FOR FORMING SELVAGES N CLOTH Erwin Pfarrwaller,Winterthur, Switzerland, assignor to Sulzer Brothers Limited,Winterthur, Switzeriand, a Swiss company Filed Dec. 27, 1967, Ser. No.693,935 Claims priority, application Switzerland, Dec. 29, 1966,18,766/66 Int. Cl. D03d 47/48 US. Cl. 139-122 3 Claims ABSTRACT OF THEDISCLOSURE In the weaving of cloth on a loom in which the weft threadsare pulled through the shed from a supply bobbin outside the shed, aselvage is formed by a method in which a tuck-in needle is subjected toa reciprocating arcuate motion generally transversely of the warps and areciprocating linear or substantially linear motion generally lengthwiseof the warps, these motions being superposed. The arcuate motionincludes a positive acceleration of the needle back toward the shed froman extreme position in which the weft-grasping hook on the needle islaterally outside the shed but vertically between the upper and lowerhalves of the shed, a deceleration which retards the passage of theweft-holding hook across the selvage portion of the width of the web ofcloth, and a reacceleration toward an inner rest position in which theneedle is retracted out of the shed and out of the way of the reed.Separate cams produce the arcuate and linear motions which aresuperposed on each other, the latter motion also including a pause timedto bring the needle briefly to rest as regards both motions while thehook is within the selvage portion of the Width of the cloth beingwoven. A third cam suitably coupled to those already mentioned effectsreciprocating motion, lengthwise of the warps, of a weft thread clampadjacent the edge of the cloth between the line of picking and aposition making it possible for the tuck-in needle to grasp the weftlast picked through the shed. A fourth cam moves the clamp up and down.

The present application pertains to subject matter related to thatdisclosed and claimed in my copending application Ser. No. 641,664,filed May 26, 1967.

BACKGROUND OF THE INVENTION The present invention relates to looms ofthe kind in which the weft supply bobbin remains outside the shed and,more particularly, to the formation of selvages on cloth woven on suchlooms by tucking into the shed the ends of the weft threads. Theinvention provides a method of forming such selvages, and apparatus bymeans of which that method may be practiced.

It has heretofore been proposed to form selvages on cloth woven on loomsof the type above described by means of a selvage tuck-in needle which,while tucking in the end of the weft, is continuously accelerated, movedinto the shed and brought to an inoperative stationary position of rest.This has the disadvantage that the weft end which is to be tucked inbecomes disengaged from the tuck-in needle at a relatively early phasein the process of shed closing by means of which the weft end is to bebound into the cloth. If the shed, which changes during tucking in, isnot closed far enough when the weft end becomes disengaged from theneedle, the weft end may spring out of the shed, particularly if it ismade of a synthetic, relatively resilient yarn which exhibits a degreeof springiness. The selvage, if formed at all, is defective. Some or allof the warp threads in the selvage region are not bound in. The objectof the invention is to improve the operating method and loom in thisrespect.

SUMMARY OF THE INVENTION According to one aspect of the presentinvention, in a method of operating a loom of the kind specified, theselvage tuck-in needle in its pivotal movement between theyarn-receiving stationary position and the inoperative stationaryposition is first accelerated, then temporarily retarded in the regionof the selvage, reaccelerated and then brought into the inoperativestationary position. According to another aspect of the invention, aloom of the kind specified has a drive which is arranged to impart tothe selvage tuck-in needle a pivotal movement between the yarn receivingstationary position and the inoperative stationary position in whichmovement the tuck-in needle is first accelerated, then temporarilyretarded in the region of the selvage, reaccelerated and then broughtinto the inoperative stationary position.

Because of the temporary lag provided by the invention in the pivotalmovement of the selvage tuck-in needle while it is tucking the weft endin, the shed is further closed than heretofore before the end which isto be tucked in leaves the needle. As the weft end leaves the hook ofthe needle, it can then cling sufiiciently to the warp threads not tospring back out of the shed. Since however the start of the pivotalmovement of the needle need be no later than in prior art practice, thespace at the edge of the cloth is, as before, clear early enough for thereturn movement (in the direction of the warp) of a selvage thread clampwhich grips the weft end immediately after picking. This is importantbecause, immediately the selvage thread clamp has surrendered the weftend to the tuck-in needle, it must return in the direction of the warpto grip the next weft in the picking line.

BRIEF DESCRIPTION OF THE DRAWING The invention will now be furtherdescribed with reference to the accompanying drawing in which:

FIG. 1 is a view in elevation of a loom, seen from the cloth end, intowhich the invention may be embodied and on which the invention may bepracticed;

FIG. 2 is a plan view on a larger scale, illustrating the movement of atuck-in needle in the loom shown in FIG. 1;

FIGS. 3 to 6 illustrate other positions of the needle shown in FIG. 2;

FIG. 7 is a fragmentary vertical section through the loom shown in FIG.1 along a plane parallel to the warps and illustrating one of thetuck-in needles and weft thread clamps thereof, together with drivingmechanism for those elements;

FIG. 8 is a diagrammatic plan view of the tuck-in needle of FIG. 7,showing the mechanism which imposes an angulanmotion thereon;

FIG. 9 is a developed view of the profile of the cam 57 shown in FIG. 8;and

FIGS. 10 to 13 are four diagrams illustrating operation of the loom.

DESCRIPTION OF THE PREFERRED EMBODIMENT The loom shown in FIG. 1comprises two upright side frames 1 and 2. connected by a central crossmember. Between the side frames there are disposed at warp beam 17,heddle frames 9, a reed 8 and a cloth beam consisting of two portions 3and 18. The side frame 2 carries a picking motion 13. From this pickingmotion shuttles 12 move through the shed along a shuttle guide 14,picking through the shed on each travel a weft 10 drawn oil? a supplybobbin 11 which remains outside the shed. Each 3 shuttle 12 goes to acatching motion 15 on the side frame 1.

On the left in FIG. 1 there is a driving motor 7, from which power istransmitted by a flywheel 6 to a main drive shaft 5 for the loom. Thismain shaft 5 drives the moving parts of the loom, e.g. the heddle frames9, the reed 8, the picking motion 13 and catching motion 15.

A selvage tuck-in device 16 is associated with each of the motions 13and 15. A corresponding tuck-in device 21 for the dividing selvage inthe middle of the loom is mounted on a rod 20. The devices 16 and 21,more fully described below, tuck the ends of each weft picked throughthe shed 88 (FIG. 7) into the next shed, so that selvages are formed atthe edges of the cloth webs 4 and 19 (FIG. 1).

Each of the selvage tuck-in devices 16 and 21 includes a tuck-in needle23 with a hook 22 at the end thereof (FIGS. 2 to 6). The movement of theneedle is shown in detail in FIG. 2. Point A is the point in the hookwhich is occupied by a weft end caught by the hook. In the course ofeach loom cycle, i.e. between one pick and the next, and during whichthere occurs a complete rotation of the main shaft 5, point A followsthe closed curve 24 shown in FIG. 2. The corresponding positions of themain shaft 5 are marked on the curve 24 in degrees of are. The variousphases of the loom cycle, and in particular of the motion of the tuck-inneedles, may thus be identified with the angular position of the mainloom shaft.

At 40 to 50 of the loom cycle relative to a position of the main shaft,for which the corresponding position of the hook 22 is labeled 0/360 inFIG. 2, the needle 23 is in its inner inoperative position of rest atthe bottom of FIG. 2, which position for the needle is identified by thereference character 23a. As the shaft rotates past 50 of its cycle theneedle moves horizontally from the position 23a along the curve 24, thismotion appearing as an upward motion in the plan view of FIG. 2. At 120of the loom cycle the needle moves to the left in FIG. 2, and until 140it moves in the direction of the warp threads 25 towards the rear of theloom (i.e. towards the warp beam 17 of FIG. 1). During this movement theneedle presses upwardly against the warp threads of the lower shed whichare immediately above it, the shed being open. This movement brings theneedle 23 into position ready to pass into the shed 88 (FIG. 7).

Between 140 and 150, the needle turns again into a path substantiallyparallel to the weft threads and passes into the shed 88. At 190 thehook 22 passes out of the shed 88 at the edge thereof. At the same timeit turns to the right (i.e. towards the front of the loom) and moves,partly in the direction of the warp threads 25 and partly in thedirection of the weft, into the yarnreceiving position shown for it inFIG. 4, where the arm is stationary, the drive shaft 5 being now at 250.This position of the needle is identified by reference character 23b.

The end 26 of the weft 10 just picked is held taut by a selvage threadclamp 27 described in detail below. This clamp moves towards the frontof the loom (cloth end) as indicated by arrow 29 from a position 2712therefor (FIG. 4) to a position 270 (FIG. 5), in which the weft end 26is drawn over the hook 22 of the tuck-in needle. Meanwhile, the needle23 (i.e. its hook 22) accelerates from its stationary outermost positionshown in FIG. 4 and pivots back into the shed, substantially parallel tothe weft. The selvage thread clamp 27 then moves on to a reversing orforwardmost position 27d (indicated in FIG. 5) corresponding to anangular position 300 for the shaft 5.

At about 280 of the loom cycle, when the hook has returned into the shedas shown in FIG. 5, the needle is temporarily retarded, retardationbeginning at approximately the position shown for needle at 23c in FIG.5. The needle stops in the position 23d (FIG. 6), i.e. its pivotalmovement is interrupted. This stoppage last until 4 310. Theintermediate stationary position 23d leaves the hook 22 within theregion of the selvage 31 (FIGS. 2, 6), whose width is equal to thelength of the weft end 26 to be tucked in and which generally includestwice as many wefts as the ground 30 of the cloth.

Meanwhile the thread clamp 27 is moving back to the left as indicated byan arrow 29a in FIG. 6, towards the rear or warp end of the loom.

As the driving shaft turns past 310, the needle 23 is re-accelerated andpasses through the positions at 330, 340, 350 and 360 (FIG. 2) back intothe inoperative stationary position 23a, in which the needle 23 isforward of the fell 40 at which the reed 8 beats up the weft. Thismovement of the needle 23 is repeated in each cycle of the loom.

The movement of the tuck-in needle is produced by the means describedbelow.

Each of the selvage tuck-in devices 16 and 21 includes a cam 34 which isattached to a shaft 33 (FIG. 7) driven at the speed of the shaft 5. Thiscam produces a translatory movement of the needle 23 of its tuck-indevice in directions parallel to the length of the warp. A followerroller 35, running on the cam 34, is mounted on a lever 37 pivoted at 36and biased counterclockwise in FIG. 2 by a compression spring 50. Thislever has a forked end 38 in which there engages a peg 39 attached to acarriage 41, which is mounted in guides to move backwards and forwards,parallel to the warps, as indicated by an arrow 42 (FIGS. 7, 8). Cam 34thus effects translational movement of the carriage 41, and thereby ofthe needle.

Two levers 44 and 45 are fixed to a vertical pin 43 journaled in thecarriage 41. The selvage tuck-in needle 23 is attached to the arm 44. Ablock 46 pivoted to the arm 45 runs in a slot 47 in a carriage 48, whichis provided to effect the pivotal movement of the needle 23.

The carriage 48 is movable in casing 13 with respect to the pin 43 asindicated by arrow 49 (FIG. 8), transversely of the motion of carriage41. Carriage 48 contains a second slide 51 along which moves a block 52.This block is pivoted to one end of a lever 53 which can oscillate abouta stationary pivot 54. The lever 53 is biased by a tension spring 60 andcarries a roller 56. This roller rolls on a cam 5'7, which causes thepivotal (as distinguished from translational) movement of the tuckinneedle and rotates at the speed of the driving shaft 5.

Two further earns 61 and 62 (FIG 7) are also attached to the shaft 33.These earns produce the movement of the selvage thread clamp 27 andcooperate with follower levers 63 and 64 biased counterclockwise in FIG.7 by compression springs 101 and 102. The lever 63 pivots at 65, thelever 64 at 66. The lever 63 carries a guide 68, pivoted to lever 63 at67, for a rod 71 pivoted at 69 on the lever 64. The selvage thread clamp27 is attached to the end of the rod 71 at the left in FIG. 7.

The elements 61, 63 and 68 cause the clamp 27 to move vertically in FIG.7 and also in the loom in FIG. 1 (as indicated by an arrow 103), whereasthe elements 62 and 64 caused it to carry out the horizontal movementsdescribed in connection with FIGS. 4 to 6 and indicated by the arrows 29and 29a in FIGS. 4 and 6. The vertical and horizontal movements aresuperimposed on each other.

The development 81 of the pivoting cam 57 is represented in FIG. 9. Thiscam produces the pivoting movement of the tuck-in needle 23 (arrow 82 inFIG. 8) causing the actual tucking in of the weft end 27.

Operation is as follows. During operation, the pivoting cam 57 andtherefore the development 81 of its profile progress in the direction ofarrow 83 (FIG. 9), so that the roller 56 comes on to the upward slope 84(FIG. 8). The lever 53 hence rotates clockwise in FIG. 8, the carriage4-8 is pulled downwards (as seen in the figure), and the lever 44 pivotsclockwise, the block 46 moving to the right along its slot 47. Thisbrings the needle 23 gradually out of its inoperative position 23a intothe position which it occupies at 120 of the loom cycle (FIG. 2).

The low portion 85 of the translatory cam 34 now moves under the roller35, so that the translatory carriage 41 and pivot 43 move to the left inFIGS. 7 and 8. The tuck-in needle 23 thus moves leftward in FIG. 2 tothe positions for 130, 140. In this region the needle 23 presses upwardson to the lower shed warp threads 25a (FIG. 7). The threads 25a whichare over the tuck-in needle at this moment are slightly raised thereby.

As the arm 44 pivots further, the needle moves to the positions for 150,160, 190 (FIG. 2). In this region it passes through the shed 88.

When the lobe 89 of the translatory cam 34 becomes effective, thecarriage 41 and needle 23 move back to the right in FIGS. 7 and 8. Theneedle 23, pivoting out of the shed, therefore also moves forwardly andtakes up the yarn-receiving stationary position 23b at 250 (FIGS. 2 and4). I

During the subsequent tucking-in movement (the arms 44, 45 rotatingcounterclockwise in FIG. 8), first the downward slope 105 of thepivoting cam 57 comes into effect, accelerating the needle 23 and movingit into the shed 88. The pivotal movement of the needle is then retardeduntil the portion 92 of the cam 57, between 300 and 310, comes beneaththe roller 56. Portion 92 is circular. In this interval, therefore, thepivoting of the elements 53, 44 and 45, and therefore of the needle, isinterrupted. Since the circular lobe 93 of the translatory cam 34 takeseffect from about 295 onwards, the movement of the carriage 41 and pivot43 is interrupted at the same time as the needle is in its intermediatestationary position at 300 to 310, i.e. the translatory movement of theneedle 23 is also interrupted and the needle stops completely.

The low portion 95 of the pivoting cam 57 now comes beneath the roller56, so that the pivotal movement of the levers 53 and 44, 45 continuesand the needle 23 is reaccelerated. Finally, the needle returns to theinoperative position 2311 in FIG. 2. The cycle is now repeated.

In each of the diagrams of FIGS. 10 to 13, the angular position of thedriving shaft 5 is shown on the abscissa. The ordinate in FIG. 10 givesthe position of the needle frames 9, that in FIG. 11 the position of thereed 8, that in FIG. 12 the pivoting speed or angular velocity of theneedle 23, produced by the cam 57, and that in FIG. 13 the correspondingacceleration. During the beating up movement of the reed at 50 (curve Cin FIG. 11) the shed is opened as shown by the two curves D, E in FIG.10. Between 105 and about 290, the shed is open and the next weft ispicked into the shed 88. At 245 the heddle frames 9 begin to change shedand the shed is gradually closed, the shed closing fully at in the nextrevolution of the main shaft. Of course the invention is not limited tothese particular phases for the closing of the shed.

As the speed curve F in FIG. 12 shows, the inoperative stationaryposition 23a is between 40 and 50 of the loom cycle. The speed betweenpositions 23a of FIG. 2 and 23 of FIG. 4 is plotted as negative,representing clockwise rotation of the needle as seen in FIGS. 2 to 6.At 250 the speed is Zero again. In the course of the counterclockwiserotation from position 23b (FIG. 4, hook 22 outside the shed) toposition 23a (inner rest position, FIG. 2) the angular velocity orspeed, which must be positive for such rotation, becomes temporarilyzero between points R (300) and S (310), and it then reverts to apositive value until the needle 23 has returned to position 23a. It willbe seen from FIG. 2 that during the phase or the loom cycle extendingbetween 300 and 310, the hook 22 is, crosswise of the loom, between theinner and outer edges of the selvage 31. Vertically it is inside theshed, i.e. betwen the upper and lower halves 25b and 25a of the shedshown in FIG. 7.

The acceleration curve G in FIG. 13, accordingly, gives first a positiveacceleration Z after the 250 position, then a negative accelerationbefore point T (i.e. a retardation W), then zero acceleration betweenpoints T and U, and a positive acceleration X after point U. Theacceleration is negative at W notwithstanding the positive value of theassociated speed, which this negative acceleration is in the process ofreducing in absolute magnitude.

As FIG. 10 shows, the distance between the warp threads 25a and 25b(FIG. 7) moving from the upper and lower shed positions towards thecenter is already somewhat reduced at 310, so that the weft end 26 onthe hook 22 is held by the warp threads on both sides of it and cannotspring back out of the needle. As the elements of the loom move on afterthe 310 position, the heddle frames move further towards the closed shedposition, which is finally reached at 20 after the start of the nextcycle. The weft end 26 leaves the hook 22 and is bound in by the warpthreads. After the shed opens again, the reed 8 heats up both thetucked-in end of the last weft but one, and the weft just picked.Another weft is then picked, and so on.

The acceleration curve of FIG. 13 therefore shows that when the hook 22starts to return, at 250 of the loom cycle, from its extreme outermostposition shown on curve 24 in FIG. 2, the hook first suffers positiveacceleration over an interval of time Z, reaching at the end of thattime, i.e. at about 275, a counterclockwise or positive angular velocityindicated at L in FIG. 12. In the particular exemplary operationillustrated, as soon as the acceleration falls to zero at the end ofinterval Z, it passes to a negative value, so that the hook on enteringthe shed is decelerated over a time interval W terminating at 300, bywhich time the hook has been reduced to zero angular velocity, asindicated at -R in FIG. 12. The hook is held at rest between 300 and310, with zero angular velocity and zero angular acceleration. It thensuffers a positive acceleration over a time interval X, acquiring asubstantially uniform, counterclockwise or positive angular velocity M(FIG. 12) which is maintained until above 10 of the next cycle. Then theneedle is braked, i.e. undergoes negative acceleration, as appears atthe left end of FIG. 13, to reduce its velocity to zero at 40.

In another embodiment, the speed, as indicated by the broken-line curveK in FIG. 12, does not drop to zero between 300 and 310, and theacceleration curve in FIG. 13 moves from the negative portion W shown bybroken lines directly into a positive portion X. In this case therefore,the tuck-in needle 23 is only braked, and is not brought to a completestop.,This still gives the desired effect, i.e. the weft end 26 is stillheld better by the warp threads 25a and 25b which are in process ofclosing the shed.

The interruption or braking of the tucking-in movement of the needle 23,instead of extending over 10 of the rotation of the driving shaft, mayextend over a different range, for example 5 or 15. Also, it may forexample occur between 290 and 300. The range in 'which the needle 23 istemporarily retarded or stopped, and then re-accele'rated depends on theoperational conditions, more particularly on the length of the weft ends26 which are to be tucked in, i.e. on the width of the selvage 31. Theintermediate retardation or stopping of the needle 23 must in any casetake place within the selvage 31, so that the weft end 26 is still beingheld by the hook 22.

In a. loom with a single web of cloth and a continuous cloth beam, thetuck-in device 21 for the dividing selvage (FIG. 1) is unnecessary.Tuck-in needles 23 need only be provided in the tuck-in devices 16 atthe edges of the cloth.

While the invention has been described hereinabove in terms of apresently preferred mode of practice of the method thereof and in termsof a number of presently preferred embodiments of the apparatus thereof,the invention itself is not limited thereto but includes allmodifications on and departures from the practice and embodimentshereinabove described properly falling within the spirit and scope ofthe appended claims.

I claim:

1. In the weaving of cloth from warp and weft threads on a cyclicallyoperating loom in which the warp threads are formed into successiveSheds and in which each Weft thread is picked through a shed from asupply bobbin remaining outside the shed on one side thereof and is cutoff on that one side of the shed to provide a weft thread having endsextending beyond the shed on each side thereof, a method of tucking inat least one of said ends of each weft thread to form a selvage whichcomprises accelerating the tip of a tuck-in needle toward the shed froma position of rest outside the shed on one side thereof, grasping saidend of the weft thread with the tip of the needle in the course ofreturn of the tip toward the shed, decelerating the needle while the tipthereof is in the portion of the shed corresponding to the selvageportion of the width of the cloth, and reaccelerating the needle towardan inner position of rest.

2. A method according to claim 1 wherein said deceleration is continuedto bring the needle tip to rest with the tip thereof grasping the weftend in the said portion of the shed.

. 3. A method according to claim 2 including the further step of holdingthe needle stationary for a fraction of the loom cycle between saiddecelerating and reaccelerating steps.

References Cited UNITED STATES PATENTS 2,185,308 1/ 1940 Pfarrwaller.

HENRY S. JAUDON, Primary Examiner

